Room Temperature Allenation of Terminal Alkynes with Aldehydes

A gold-catalyzed room temperature allenation of terminal alkynes (ATA) with aldehydes affording 1,3-disubstituted allenes with diverse functional groups has been developed by identifying a gold(I) catalyst and an amine. The practicality of this reaction has been demonstrated by a ten gram-scale synthesis and the synthetic potentials have been demonstrated via various transformations and formal total synthesis of (-)-centrolobine. Mechanistic studies revealed that the gold catalyst, the aldehyde effect, the fluoroalkyl hydroxyl solvent (TFE or HFIP) and the structure of amine are vital in this room temperature ATA reaction.

Automated summary

The study developed a gold-catalyzed room temperature allenation of terminal alkynes with aldehydes, providing 1,3-disubstituted allenes with diverse functional groups, and demonstrated the practicality and synthetic potentials of this reaction. Mechanistic studies showed that the gold catalyst, the aldehyde effect, the fluoroalkyl hydroxyl solvent, and the structure of the amine are essential for this room temperature ATA reaction.